Field of the Invention
The present invention relates to: a graphics processing apparatus that performs graphics processing to generate a screen image to be displayed on a display; an image processing apparatus provided with this graphics processing device; a graphic processing method; and a recording medium.
Description of the Related Art
The following description sets forth the inventor's knowledge of related art and problems therein and should not be construed as an admission of knowledge in the prior art.
For example, an image processing apparatus such as a multi-functional digital machine i.e. a multi-function peripheral (MFP) performs graphics processing to display an operation screen on a display of its operation panel. Specifically, the image processing apparatus performs graphics processing by a central processing unit (CPU) i.e. a general-purpose computing device used in the image processing apparatus itself or by a graphics processing unit (GPU) i.e. a special-purpose computing device that performs microprocessing optimally for graphics processing.
As referred to a straight line L1 in FIG. 12, the time required for graphics processing by the CPU increases in proportion to the pixel count of the display. In contrast, as referred to a straight line L2 in FIG. 12, the time required for graphics processing by the GPU increases only very slightly in proportion to the pixel count of the display, or rather, it is almost constant. In this case, however, it is troublesome that the time for draw call batching as a preprocessing step of graphics processing is further required. The draw call batching is combining the attributes of all screen elements, such as textures, materials, and coordinates, into a single batch of data in a certain format. The CPU performs this draw call batching and issues a command for graphics processing to the GPU using the obtained data.
Comparing the time required for graphics processing between the CPU and the GPU, as is understood from FIG. 12, the CPU will perform graphics processing faster if the display has a low pixel count, and the GPU will perform graphics processing faster if the display has a high pixel count.
As a solution to this problem, there is a computer system that allows a CPU to perform graphics processing to generate a low-resolution video and that allows an independent GPU to perform graphics processing to generate a high-resolution or high-bit-rate video, as described in Paragraph [0044] of Japanese Unexamined Patent Application Publication (Japanese Translation of a PCT International Patent Application Publication) No. 2013-516697.
As is evident from the inventor's study, however, the time required for graphics processing by the CPU varies depending on the number of the screen elements composing a screen image to be displayed on the display, and in contrast, the time required for graphics processing by the GPU hardly varies depending on the number of the screen elements, or rather, it is almost constant. Specifically, if the number of the screen elements is low and the pixel count is high, the time required for graphics processing by the CPU is shorter than the other; if the number of the screen elements is high and the pixel count is low, the time required for graphics processing by the CPU is longer than the other. That is because the CPU needs to repeat graphics processing for one screen element until it reaches the number of the screen elements composing one entire screen image.
The heretofore known technique is configured to judge which device, the CPU or the GPU, should perform graphics processing with reference to the pixel count of the display as described above, but it cannot select the CPU or the GPU, whichever will perform graphics processing really faster.